look it's the nutes that will hurt the seedlings. i could grow treetops with m.g but i wouldn't there are much better soils out there plus better mediums..try cocoa. anyway you can raise the ph by adding tap water that is set out overnight or add calmag...now go do some fucking research that is why we have the forums...use the organic it is the mildest and is recomened for veggies. add a bunch of perlite and go play....when you are ready to grow do your research.